In the past, it has been common to equip radio pagers and radio data receivers with clips to allow those devices to be attached to the user's clothing or belt. Commonly, such clips are permanently attached to the devices, or are detachable or are attached to a holster in which the pager may be carried. A major advantage of clothing or belt attachment is that mechanical vibrating alert devices, which are widely used, are most effective when the pager or data receiver is firmly coupled to the user's body and which occurs with clothing or belt attachment.
It is desirable to be able to read the display of such a device when clipped to the belt. This is convenient for a device with a top mounted display, but front face display units require rotation through approximately 90 degrees. A display is inverted when viewed from the belt, and it is necessary to also provide for display reversal for reading on the belt.
Traditionally designed belt clips allow a very limited angle of rotation to facilitate viewing, typically 30 degrees. One model of pager has a separated belt clip which attaches to the pager only at a pivot at the top of the pager, thus providing a large angle of rotation. Another, which is described in U.S. Pat. No. 4,802,241, has a two part clip with a wide opening angle but with the closure spring exposed which, in use, traps dirt and becomes unsightly.
Clips attached to pagers are awkward to attach and to remove from belts, and to overcome this, pager manufacturers commonly provide optional holsters, which provide for belt attachment and at the same time, ease of extraction of the pager for inspection of the display.
When working at a desk it is sometimes desirable to move the pager to the desk so that incoming messages may be conveniently observed. Some pager manufacturers have designed holster products and pager clips such that these can be used as desk stands. However, because this is not the primary application they are commonly poorly suited to this use.
The current trend is to make pagers as thin as is possible. Vibrating alert devices ("vibrators") have very high current consumption compared with audible or visual alert modes and pagers with built in vibrators require relatively large batteries. A previous invention of two of the present inventors involves the integration of a vibrator in a holster for a pager or data receiver. However, that configuration required that the vibrator be driven from the power source within the pager or data receiver. We have discovered that major benefits can be derived from mounting both the vibrator and its power source in a holster or detachable clip, i.e. the pager itself need not carry the power supply for the vibrator, thus allowing the pager to be minimized in size and weight, yet allow it to use a vibrating alert in the carrying position in which the pager uses such form of alert.